An alternative framework for the study of different dark matter candidates consists of simplified models [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, in which the mediator between the dark matter and the Standard Model (SM) sector is also included in the particle spectrum. In this context, studies of dark matter can be done with only a few parameters
and a systematic study can be performed on a large class of dark matter models. However, these simplified models do not come free of problems.
They present issues of unitarity and gauge anomalies [8]}, [9]}, [10]}, [11]}, [12]}. In particular, when considering indirect
detection and the predictions for gamma lines from dark matter annihilation, a complete anomaly-free dark matter theory is needed, see
for example [13]}, [14]} for a detailed discussion.
